Obtenção de nanopartículas de prata utilizando açúcar mascavo: um estudo da influência das condições de síntese

Abstract

Nanotechnology plays a crucial role in developing distinct materials on a manometric scale with broad potential application in different areas of knowledge. Among the types of nanometric materials produced, the metallic nanoparticles (NPMs), among them the silver ones, have gained attention from the scientific community due to their properties that allow their use in biomedicine, catalysis, and environmental areas, among others. Commonly silver nanoparticles (AgNPs) are synthesized by physical and chemical methods, which use toxic chemicals to impact the environment and humans. An exciting alternative to chemical and physical methods of preparing metal nanoparticles is green synthesis. The green synthesis used natural chemical compounds present in plants, food, etc. The present study aims to synthesize silver nanoparticles (AgNPs) by green synthesis using an aqueous extract of brown sugar as a reducing and stabilizing agent and silver nitrate (AgNO3) as precursor salt. During the green synthesis of the nanoparticles, different synthesis conditions were studied, such as the volume of the extract, salt concentration, temperature, reaction time, and pH of the solution. The stability of the synthesized silver nanoparticles (AgNPs) was also investigated. Confirmation of AgNPs formation was performed by visual observation and Spectroscopy in the ultraviolet-visible (UV-vis) region. The formation of AgNps was detected mainly by the change in the coloration of the reaction mixture from colorless to brown after treatment with AgNO3. Through UV-Vis spectroscopy, the authenticity of AgNPs was confirmed through the plasmon resonance band at 449 nm. The AgNPs nanoparticles were stable for 60 days under refrigeration at 5 oC and in the absence of light. FT-IR analysis of brown sugar revealed chemical groups such as CO, OH, COO, and NH that may reduce the nanoparticles. The synthesis of AgNps using brown sugar showed to be feasible besides being a simple and eco-friendly process.